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An administrator is testing the Cisco Nexus 1000v switch on top of a Cisco UCS Blade. They realize that the test VM traffic is not marked correctly after it leaves the Cisco UCS B-series blade.
What is the reason for seeing this behavior?
A. The Cisco UCS does not support QoS marking
B. The Cisco UCS QoS policy applied to the blade has the host control set to "none."
C. The Cisco Nexus 1000V Series Switches do not support QoS marking.
D. The Cisco Nexus 1000V Series Switch QoS marking has not been enabled with "feature gos."
Correct Answer: B
Explanation/Reference:
Explanation: https://www.cisco.com/c/en/us/support/docs/switches/nexus-1000v-switch/117541-configure-qos- 00.html#anc6
Whether UCS controls the CoS for a vNIC or not strictly depends on the Host Control Field of the QoS Policy, which is assigned to that particular vNIC.
If None is selected, then UCS assigns the CoS value associated with the Priority Class given in the QoS policy. It disregards any of the settings implemented at the host level by the Nexus 1000v.
If Full is selected and the packet has a valid CoS assigned by the Nexus 1000v, then UCS trusts the CoS settings assigned at the host level. Otherwise, Cisco
UCS uses the CoS value associated with the priority selected in the Priority drop-down list.
The Milano QoS policy has a Host Control of Full, which means that the Gold Priority (CoS 6) is ignored and the Nexus 1000v setting is trusted.
The correct answer is "The Cisco UCS QoS policy applied to the blade has the host control set to "none." The other answers are not correct, or are not causes for the behavior.
